According to prior arts of a slide unit of a clamping head on a plastic zipper bag, referring to FIG. 1, the slide unit 92 of the clamping head is installed at the top edge of a clamping portion 91 of an opening 90 of the zipper bag 9. By sliding the slide unit 92 of the clamping head on the clamping portion 91, the opening 90 of the zipper bag 9 is available to be opened or closed. However, when the slide unit 92 of the clamping head is assembled at the opening 90 of the zipper bag 9 of the prior arts, the lower slide unit 92 of the clamping head should be pulled outwards opening firstly in order to enlarge the open of the lower slide unit 92 of the clamping head. Thereby, the slide unit 92 of the clamping head is installed at the clamping portion 91 of the zipper bag 9. A removing sheet of the slide unit 92 of the clamping head removes the clamping portion 91 and inserts in the center thereof so that the assembly is finished finally.
However, when the slide unit 92 of the clamping head of the prior art is installed at the clamping portion 91, the lower part of the slide unit 92 of the clamping head should be pulled outwards to open (referring to FIG. 2). The slide unit 92 of the clamping head is subjected to a change in shape due to the excessive pulling force which could result in breakage of the slide unit 92 of the clamping head resulting in a loss of manufacturing cost. In addition, the assembly of the prior art requires an additional manpower as a worker has to manually pull open each lower part of the slide unit 92 of the clamping head one by one. The assembly processes of the prior arts result in loss of manpower and assembly time. In today's ever evolving business environment, a manufacturing procedure should be simple, convenient and fast in order to win a company any competitive edge. If a manufacturing procedure requires manual assembly by hands, the productivity is not only limited but would result in loss of manpower and manufacturing inefficiency. The continuous and automatic assembly is capable of enhancing productivity and reducing manufacture costs which would result in a more competitive edge. Therefore, the novelty of the present invention serves to overcome the above-mentioned defects of the prior arts and improve the assembly procedure of the slide unit of the clamping head on the zipper bag.